Eventuate is a platform that tackles the distributed data management challenges inherent in a microservice architecture. https://eventuate.io/

1. @crichardson
Overview of the Eventuate
Platform
Chris Richardson
Founder of Eventuate.io
Founder of the original CloudFoundry.com
Author of POJOs in Action
@crichardson
chris@chrisrichardson.net
http://microservices.io
http://eventuate.io
Copyright © 2020. Chris Richardson Consulting, Inc. All rights reserved

2. @crichardson
Agenda
Overview of Eventuate
Using Eventuate Tram
Event Sourcing with Eventuate Local

3. @crichardson
About Eventuate
Distributed data management platform for microservices
Programming model based on
Transactional, asynchronous messaging
Sagas
CQRS
Event Sourcing
Java/JVM (Spring Boot/Micronaut), NodeJS, .NET
http://eventuate.io/

4. @crichardson
Microservice
Architecture
Database per
Service
Saga CQRS
Choreography-
based
Saga
Orchestration-
based saga
Domain Event
Async
Request/
Response
Event SourcingTransactional
Outbox
Motivating
Pattern
Solution
Pattern
Solution A Solution B
General Specific
Eventuate Local
Eventuate through microservices patterns
Key distributed data management patterns
Key enabling patterns
Idempotent
Consumer
Needed for loose design-time and runtime coupling
Implements queries that span servicesImplements transactions that
span services
Eventuate Tram

5. @crichardson
Eventuate architecture
Eventuate
framework
Eventuate
framework
Relational
database
Message
broker
Eventuate
CDC
service
Send message
Publish event
Consume message/event
Transactional Outbox/
Event Sourcing
Service Service
Idempotency
Sharding

6. @crichardson
About the Eventuate CDC
service
Publishes messages inserted into the message/events table to
the message broker:
Tails MySQL/Postgres transaction log
Uses polling for other databases
Spring Boot application/available as a Docker container
Scaling - CDC per service database

7. @crichardson
Supported infrastructure
Databases: Postgres, MySQL, SQL server, etc.
Message Brokers: Apache Kafka, Apache ActiveMQ,
RabbitMQ and Redis Streams

8. @crichardson
start.eventuate.io: enhanced
Spring Initialzer

9. @crichardson
Described in my book
Examples are all
Eventuate-based
https://microservices.io/book

10. @crichardson
Agenda
Overview of Eventuate
Using Eventuate Tram
Event Sourcing with Eventuate Local

11. @crichardson
Eventuate Tram
=
Transactional messaging and
sagas for services using
traditional persistence

12. @crichardson
Eventuate Tram features
Transactional messaging
Events Commands
Saga orchestration

13. @crichardson
Eventuate Tram architecture
Eventuate
Tram
framework
Eventuate
Tram
framework
Message
broker
Eventuate
CDC
service
Publishes messages inserted into MESSAGE table
Relational database:
MySQL
Postgres, ….
MESSAGE
Table
INSERT INTO
MESSAGE….
Subscribe to
messages
Apache Kafka
ActiveMQ
RabbitMQ
Service Service

14. @crichardson
ACID transaction
Eventuate Tram: sending a message
ChannelEventuate
Tram
Producer
Eventuate
Tram
Consumer
Optional
partition key
Message
Scalable
Ordered, at-least
once delivery
DB

15. @crichardson
ACID transaction
Eventuate Tram: consuming a
message
Channel
Message
Eventuate
Tram
DB
Built-in idempotent
consumer
Scalable
Ordered, at-least
once delivery

16. @crichardson
Transactional messaging
Implements
transactional outbox

17. @crichardson
Events: publishing
Events = Messages++
aggregateType = channel
aggregateId is the partition key = ensures ordering of events
from a given aggregate

18. Events: consuming

19. @crichardson
About commands
Builds on transaction messaging
Asynchronous Request/response
Request message has headers:
commandType - used to select command handler
replyTo - channel to send reply to

20. Sending commands

21. @crichardson
Handling commands

22. @crichardson
Saga orchestration - orchestrator
Sequence of
steps
step = (Ti, Ci)
Saga’s Data
https://github.com/eventuate-tram/eventuate-tram-sagas-examples-customers-and-orders

23. @crichardson
Customer Service command
handler Route command
to handler
Reserve
credit
Make reply message

24. @crichardson
Agenda
Overview of Eventuate
Using Eventuate Tram
Event Sourcing with Eventuate Local

25. @crichardson
About Eventuate Local
Event Sourcing framework for Java/Spring Boot/Micronaut
Event store built on open-source technologies
Database: “JDBC” databases: MySQL, Postgres, SQL
Server, …
Message broker: Apache Kafka

26. @crichardson
Eventuate Local architecture
Eventuate
Local
framework
Eventuate
Local
framework
Apache Kafka
Eventuate
CDC
service
Publishes messages inserted into EVENTS table
Relational database:
MySQL
Postgres, ….
EVENTS
Table
INSERT INTO
EVENTS….
SELECT …
FROM EVENTS
Subscribe to
messages
Service Service
Event Store

27. @crichardson
Command-side logic

28. @crichardson
Customer command processing

29. @crichardson
Customer applying events

30. @crichardson
Creating a Customer
save() concisely specifies:
1.Creates Customer aggregate
2.Processes command
3.Applies events
4.Persists events

31. @crichardson
Command side event handler
Implements idempotency

32. @crichardson
Query-side logic

33. @crichardson
Query-side event handler

34. @crichardson
@crichardson chris@chrisrichardson.net
http://eventuate.io
Questions?